Lesson 39 · Unit 5

IA Day 11 —
Material Decisions

Add material reasoning to your redesign ideas: component by component, requirement by requirement, evidence by evidence.

80 minutesIA + B3.1

Guiding question: Can every important material decision in your redesign be traced to a requirement and evidence?01

Today’s destination

By the end of class, you should be able to…

Map components

Separate the product into meaningful material decisions.

Use B3.1 evidence

Connect properties, aesthetics and context to each choice.

Distinguish prototype vs final

Do not confuse modelling material with intended production material.

Improve IA annotations

Make material reasoning visible on the page.

Success check: Leave with at least one component-level material choice supported by evidence.

IA DAY · material reasoning02

Prototype material

Chosen to test an uncertainty

Foam, cardboard, PLA or substitute hardware may be ideal for modelling speed even if they are not intended for manufacture.

≠

Intended material

Chosen for final product requirements

Must be justified against performance, aesthetics, cost, availability, sustainability and relevant manufacturing context.

Be explicit about what each material choice represents03

Annotation pattern

Component: handle insert

Requirement: secure wet grip + comfort

Material property: compliant textured elastomer surface; appropriate chemical resistance for cleaning

Evidence: user grip test + supplier datasheet

Decision: use insert only at contact zones to reduce material while preserving grip

Requirement → property → evidence → decision04

60+

Make a component/material map
Identify which parts require different material behaviours.

Prioritize evidence
Choose the 2–4 most relevant criteria per component.

Add research
Datasheets, tests, user feedback or credible secondary sources.

Annotate your concepts
Show why the material choice supports the redesign.

IA studio · component by component05

Conference questions

Why does this component need a different material from the surrounding part?

Which exact property—not “durability” as a vague word—supports your decision?

What aesthetic characteristic or finish matters here?

How do cost, availability or sustainability affect the choice?

What evidence would make you change the material?

“Because it is strong” is usually not enough. Which strength? Under what load? Compared with what alternative?

B3.1 · specificity check06

Self-audit

I distinguish prototype materials from intended product materials.

Important components have relevant physical/chemical/mechanical criteria.

Where relevant, I include texture, form, colour or finishing.

I have considered cost, availability and sustainability.

At least one important choice is supported by primary and/or secondary research.

My annotations explain the decision clearly to another reader.

Next: sustainability gives you a larger systems lens for these same decisions.

IA + B3.1 · evidence audit07

Exit ticket

Before you leave…

1. Identify one component whose material choice is now justified with evidence.

2. Name the requirement/property link supporting that choice.

3. Identify one material decision that still needs research or testing.

Next lesson

Design for Sustainability

Keep the evidence chain moving: user → research → decision → test.

Curriculum alignment
IA application of B3.1: select materials by relevant physical/chemical/mechanical properties, aesthetics, cost, availability and sustainability; justify using primary/secondary research. Supports Criterion C annotations and later Criterion D development.

Lesson complete8 slides

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IB Design Technology SL · Lesson 3908

IA Day 11 —Material Decisions